Ben Hooper has taken on quite an amazing challenge - in fact, no one has ever done it before!
Looking at some of these numbers, it might not be so surprising....
Ben is going to have to face some pretty daunting physical challenges over the next 140 days, from storms to sharks...
The daily grind
And just how do you keep going during such a mammoth mission? Ben will need to eat and sleep regularly to keep himself healthy.
Ex-serviceman Ben Hooper - who's from Cheltenham - was meant to set off on his swim today but now says the expedition could be in jeopardy.
A former serviceman is about to attempt the first-ever swim across the Atlantic Ocean - raising a million pounds for charity.